Depends on many factors. Are you sure they are 'antique' eg over 100 years old. and what do you mean by 'quality'?
If you know that it is truly high quality you can ask here
http://www.hdv-lausanne.com/en/home
Or Lausanne Palace regularly holds (by appointment only) free estimates for an Antique Seller. Do ask them as I can't remember just now, the name of the Antique Business that does this.